1. Field of the Invention
This invention directs itself to a fluid transfer system utilizing siphon principles. In particular, this invention directs itself to a condensate displacement system wherein a pump is utilized to initiate siphon flow. Still further, this invention directs itself to a condensate displacement system having a flow regulation valve disposed at the inlet to the siphon assembly, providing a siphon flow rate which is proportional to the height of the condensate within the condensate reservoir. More in particular, this invention pertains to a condensate displacement system having a position sensitive switch coupled to a float for actuating a pump when the condensate level exceeds a predetermined value. Further, the position sensitive switch includes a displaceable mass for closing an electrical circuit for actuating a pump and increasing the buoyancy of the float, thereby providing hysteresis for the operation of the switch, allowing the pump to run longer than would otherwise occur.
2. Prior Art
Pumping and siphoning systems, and their combination, are well known in the art. The best prior art known to the Applicant includes U.S. Pat. Nos. 2,363,313; 3,575,004; 4,573,490; 301,391; 4,255,937; 3,011,510; 4,041,971; 2,387,483; 5,044,391; 3,491,787; 4,488,408; 4,250,629; 2,142,556; and, 4,414,997.
In some prior art systems, such as that disclosed by U.S. Pat. No. 2,363,313, there is disclosed the combined pumping and siphoning of liquids from one location to another. In such systems, both the siphon and pump have a common inlet, and thus the pump cannot be primed unless the reservoir level is above the siphon inlet. It is further noted that such systems provide for automatic flow regulation responsive to the height of fluid at the second location, but provide no means for limiting the flow responsive to the level of fluid in the supply reservoir. Since these systems have no means for regulating the flow responsive to the fluid level in the supply reservoir, air is able to enter the system when the fluid level falls below the inlet to the siphon, and thereby break the siphon, requiring the pump to be enabled when the fluid level subsequently rises. As a result of this deficiency, the disclosed system provides for air relief valves to remove entrapped air from the siphon. Such apparatus is not required by the instant invention since the flow control valve of the instant invention seals the siphon prior to the reservoir level dropping below the siphon inlet.
In other systems, such as that disclosed in U.S. Pat. No. 3,575,004, a siphon tube control device is provided to regulate the liquid flow therethrough. In such systems a valve is provided at the outlet of the siphon tube which is actuated in response to a predetermined liquid level at the tube inlet for alternately stopping and starting the liquid flow through the tube. However, such systems are not self-priming, requiring a manual initial priming thereof.